I am a big fan of BLUF (Bottom Line Up Front). Condense your entire email to a single sentence and then explain afterward.

The person you're emailing will see the key point immediately (maybe even in the lede). If they agree with you, you're good. If not, they can then read your explanation.

If the email is so complex I can't explain it one sentence, that's usually when I consider asking for a meeting or try to reduce further.

Example:

Hi {boss},

I think we should do X.

X is the best way to do Y because it can be automated and reproduced sustainably.

Etc. Etc. Supporting details...

Let me know if you'd like to meet to discuss further, {Name}